@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  --bg-deep: #0a0b0f;
  --bg-card: #12141c;
  --bg-elevated: #1a1d28;
  --border: rgba(99, 179, 237, 0.15);
  --accent: #63b3ed;
  --accent-dim: #4a9ad4;
  --human: #68d391;
  --ai: #fc8181;
  --text: #e8eaef;
  --text-muted: #8b92a3;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 24px 48px rgba(0, 0, 0, 0.4);
  --glow: 0 0 40px rgba(99, 179, 237, 0.12);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Outfit', sans-serif;
  background: var(--bg-deep);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.5;
  background-image:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(99, 179, 237, 0.08), transparent),
    radial-gradient(ellipse 60% 40% at 100% 50%, rgba(99, 179, 237, 0.04), transparent),
    radial-gradient(ellipse 60% 40% at 0% 80%, rgba(104, 211, 145, 0.03), transparent);
}

.container {
  max-width: 640px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

/* Logo */
.logo-wrap {
  text-align: center;
  margin-bottom: 2rem;
}
.logo-wrap img {
  max-height: 56px;
  width: auto;
  object-fit: contain;
  display: inline-block;
}

/* Header */
header {
  text-align: center;
  margin-bottom: 2.5rem;
}
h1 {
  font-size: 1.75rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 0.5rem;
}
.subtitle {
  font-size: 1rem;
  color: var(--text-muted);
  font-weight: 400;
}

/* Upload zone */
.upload-zone {
  background: var(--bg-card);
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 2rem;
  text-align: center;
  transition: border-color 0.2s, background 0.2s, box-shadow 0.2s;
  cursor: pointer;
  position: relative;
  box-shadow: var(--shadow);
}
.upload-zone:hover,
.upload-zone.dragover {
  border-color: var(--accent);
  background: var(--bg-elevated);
  box-shadow: var(--glow);
}
.upload-zone input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  width: 100%;
  height: 100%;
}
.upload-zone .icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 1rem;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-dim) 100%);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}
.upload-zone .hint {
  font-size: 1rem;
  color: var(--text);
  font-weight: 500;
  margin-bottom: 0.35rem;
}
.upload-zone .formats {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-family: 'JetBrains Mono', monospace;
}

/* Results panel */
.results {
  margin-top: 2rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
  display: none;
}
.results.visible {
  display: block;
  animation: fadeIn 0.4s ease;
}
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.results .filename {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  word-break: break-all;
}

.percent-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  margin-bottom: 1.5rem;
}
.percent-card {
  background: var(--bg-elevated);
  border-radius: var(--radius-sm);
  padding: 1.25rem;
  text-align: center;
  border: 1px solid var(--border);
}
.percent-card.human .value { color: var(--human); }
.percent-card.ai .value { color: var(--ai); }
.percent-card .value {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
}
.percent-card .label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-top: 0.35rem;
}
.percent-card .sentence-count {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.bar-wrap {
  height: 10px;
  background: var(--bg-deep);
  border-radius: 999px;
  overflow: hidden;
  display: flex;
  margin-top: 0.5rem;
}
.bar-wrap .segment {
  height: 100%;
  border-radius: 999px;
  transition: width 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}
.bar-wrap .segment.human { background: linear-gradient(90deg, #38a169, #68d391); }
.bar-wrap .segment.ai { background: linear-gradient(90deg, #e53e3e, #fc8181); }

.meta {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

/* Loading & error */
.loading {
  display: none;
  text-align: center;
  padding: 2rem;
  color: var(--text-muted);
}
.loading.visible { display: block; }
.loading .loading-hint {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
}
.loading .spinner {
  width: 40px;
  height: 40px;
  margin: 0 auto 1rem;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin {
  to { transform: rotate(360deg); }
}

.error-msg {
  display: none;
  background: rgba(252, 129, 129, 0.1);
  border: 1px solid rgba(252, 129, 129, 0.3);
  color: #fc8181;
  padding: 1rem 1.25rem;
  border-radius: var(--radius-sm);
  margin-top: 1rem;
  font-size: 0.9rem;
}
.error-msg.visible { display: block; }

.reset-btn {
  margin-top: 1.5rem;
  width: 100%;
  padding: 0.85rem 1.25rem;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--accent);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s;
}
.reset-btn:hover {
  background: var(--bg-elevated);
  border-color: var(--accent);
}